import Vue from 'vue'
 
// v-dialogDrag: 弹窗拖拽
Vue.directive('dialogDrag', {
   bind(el, binding, vnode, oldVnode) {
    const dialogHeaderEl = el.querySelector('.el-dialog__header')
    const dragDom = el.querySelector('.el-dialog')
   dialogHeaderEl.style.cursor = 'move'
 
    // 获取原有属性 ie dom元素.currentStyle 火狐谷歌 window.getComputedStyle(dom元素, null);
     const sty = dragDom.currentStyle || window.getComputedStyle(dragDom, null)

    dialogHeaderEl.onmousedown = (e) => {
      // 鼠标按下，计算当前元素距离可视区的距离
       const disX = e.clientX - dialogHeaderEl.offsetLeft
       const disY = e.clientY - dialogHeaderEl.offsetTop
 
       // 获取到的值带px 正则匹配替换
       let styL, styT
 
     // 注意在ie中 第一次获取到的值为组件自带50% 移动之后赋值为px
       if (sty.left.includes('%')) {
        styL = +document.body.clientWidth * (+sty.left.replace(/\%/g, '') / 100)
        styT = +document.body.clientHeight * (+sty.top.replace(/\%/g, '') / 100)
       } else {
         styL = +sty.left.replace(/\px/g, '')
         styT = +sty.top.replace(/\px/g, '')
       }

      document.onmousemove = function(e) {
         // 通过事件委托，计算移动的距离
         const l = e.clientX - disX
         const t = e.clientY - disY
 
        // 移动当前元素
         dragDom.style.left = `${l + styL}px`
         dragDom.style.top = `${t + styT}px`

        // 将此时的位置传出去
        // binding.value({x:e.pageX,y:e.pageY})
      }

      document.onmouseup = function(e) {
         document.onmousemove = null
         document.onmouseup = null
       }
     }
   }
 })